\documentclass[tikz]{standalone}

%\usepackage{pgf,pgfplots}
%\pgfplotsset{compat=1.17}
%\usepackage{mathrsfs} %provides nicer typesetting of calligraphic letters: $\mathscr{ABC}$
\usetikzlibrary{arrows}

\begin{document}

\definecolor{wrwrwr}{rgb}{0.3803921568627451,0.3803921568627451,0.3803921568627451}
\definecolor{aqaqaq}{rgb}{0.6274509803921569,0.6274509803921569,0.6274509803921569}
\definecolor{cqcqcq}{rgb}{0.7529411764705882,0.7529411764705882,0.7529411764705882}
\definecolor{rvwvcq}{rgb}{0.08235294117647059,0.396078431372549,0.7529411764705882}
\begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1cm,y=1cm]
\clip(-4.1,-3.1) rectangle (8.6,7.1);
\draw [line width=2pt,color=rvwvcq] (-2.3,4) circle (1.5cm);
\draw [line width=2pt,color=rvwvcq] (-2.3,0) circle (1.5cm);
\draw [line width=2pt,color=rvwvcq] (6.8,2) circle (1.5cm);
\draw [line width=2pt,color=rvwvcq] (6.8,5.5) circle (1.5cm);
\draw [line width=2pt,color=rvwvcq] (6.8,-1.5) circle (1.5cm);
\draw [line width=2pt,dashed,color=cqcqcq] (-0.5,3.5)-- (4.8,-0.7);
\draw [line width=2pt,color=cqcqcq] (-0.5,-0.5)-- (4.8,-1.3);
\draw [line width=2pt,color=cqcqcq] (-0.5,-0)-- (4.8,1.5);
\draw [line width=2pt,color=cqcqcq] (-0.5,0.5)-- (4.8,4.5);
\draw [line width=2pt] (-0.5,4.5)--(4.8,5);
\draw [line width=2pt] (-0.5,4)-- (4.8,2.3);
\draw (3.7,0.5) node[anchor=north west] {no edges};
\draw (-0.5,1) node[anchor=north west] {no backward flow};
\draw (-2.6,3.9) node[anchor=north west] {$N_{hi}$};
\draw (-2.5,0.2) node[anchor=north west] {$N_{lo}$};
\draw (6,5.4) node[anchor=north west] {$A^* \setminus A$};
\draw (6,2.2) node[anchor=north west] {$A^* \cap A_{hi}$};
\draw (6,-1.4) node[anchor=north west] {$A^*\cap A_{lo}$};
\draw (5.6,6) node[anchor=north west] {end of flow $f'$};
\draw (-3.5,4.5) node[anchor=north west] {start of flow $f'$};
%\draw (12,-0.5) node[anchor=north west] {end of flow $f'$};
%\draw (10,0.5) node[anchor=north west] {$(A^* \setminus A) \cup (A^* \cap A\setminus A') = A^* \setminus A'$};
%\draw [line width=2pt,color=wrwrwr] (8.7,3)-- (9.5,2.5)-- (9.5,-2.5)-- (8.7,-3.0);
\begin{scriptsize}
\draw [fill=black,shift={(4.8,5)},rotate=270] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=black,shift={(-0.5,4.5)},rotate=90] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=black,shift={(-0.5,4)},rotate=90] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=black,shift={(4.8,2.3)},rotate=270] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=aqaqaq,shift={(-0.5,-0.5)},rotate=90] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=aqaqaq,shift={(4.8,-1.3)},rotate=270] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=aqaqaq,shift={(4.8,1.5)},rotate=270] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\draw [fill=aqaqaq,shift={(4.8,4.5)},rotate=270] (0,0) ++(0 pt,3.75pt) -- ++(3.2475952641916446pt,-5.625pt)--++(-6.495190528383289pt,0 pt) -- ++(3.2475952641916446pt,5.625pt);
\end{scriptsize}
\end{tikzpicture}

\end{document}